package com.shujia.tf

import org.apache.flink.api.common.functions.FlatMapFunction
import org.apache.flink.streaming.api.scala._
import org.apache.flink.util.Collector

object Demo3FlatMap {

  def main(args: Array[String]): Unit = {

    val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment

    val linesDS: DataStream[String] = env.readTextFile("data/words.txt")

    //scala 写法
    val ds1: DataStream[String] = linesDS.flatMap(line => line.split(","))


    //java  的方式
    val ds2: DataStream[String] = linesDS.flatMap(new FlatMapFunction[String, String] {
      override def flatMap(value: String, out: Collector[String]): Unit = {
        val split: Array[String] = value.split(",")

        for (word <- split) {
          //将数据输出到下游
          out.collect(word)
        }
      }
    })


    ds2.print()


    env.execute()

  }

}
